Effect of exercise intensity on albuminuria in adolescents with Type 1 diabetes mellitus

Aims Exercise may be useful to detect patients with diabetes prone to develop persistent microalbuminuria. We studied the relationship between exercise intensity, measured as maximal oxygen consumption (VO2 max), and microalbuminuria in patients with Type 1 diabetes mellitus patients. Methods We studied 10 patients, age range 1018 years, with Type 1 diabetes who were normotensive and normoalbuminuric, with less than 10 years since diagnosis. Patients had normal renal function, without infections or clinical evidence of complications. Metabolic control was intensively adjusted in all patients. They underwent three consecutive physical exercise tests, reaching 100, 80 and 60% of the maximal cardiac frequency response. Results Eight patients had adequate to regular metabolic control. All patients had lower than predicted VO2 max values. At 60%, only three patients showed microalbuminuria in excess of 20 mu g/min, two of them had inadequate metabolic control. Post-exercise microalbuminuria exceeded normal values in nine, seven and three patients when submitted to 100, 80 and 60% of exercise intensity, respectively. Conclusions Microalbuminuria increased with exercise intensity. Sex, body composition and VO2 max were the main factors associated with microalbuminuria. The prognostic significance of albuminuria induced by intense exercise in these subjects with Type 1 diabetes is not yet known.